Core–Shell CuCo₂O₄@MnO₂ Nanowires on Carbon Fabrics as High‐Performance Materials for Flexible, All‐Solid‐State, Electrochemical Capacitors

Abstract

Abstract To boost the electrochemical utilization and area‐specific capacitance, core–shell CuCo 2 O 4 @MnO 2 heterostructured nanowire arrays on carbon fabrics are synthesized and utilized as high‐performance, binder‐free, positive electrodes for electrochemical capacitors. The electrode architecture takes advantage of the synergistic effects contributed from both the porous CuCo 2 O 4 nanowire core and the MnO 2 shell layer. The as‐prepared electrode has a high cell‐specific capacitance of 327 F g −1 , several times higher than that of CuCo 2 O 4 nanowires (57.8 F g −1 ), at a current density of 1.25 A g −1 with excellent rate capability (90 % capacitance retention at a current density of 6.25 A g −1 ) in aqueous electrolyte. A flexible, all‐solid‐state symmetrical supercapacitor is fabricated by assembling two CuCo 2 O 4 @MnO 2 nanowire‐based electrodes, a high cell‐area‐specific capacitance of 714 mF cm −2 at 1 mA cm −2 is achieved, which is much higher than values reported earlier. It delivers a high energy density of 94.3 W h cm −2 at a power density of 0.4757 mW cm −2 for a voltage window of 1 V. Highly stable electrochemical performance over 3000 cycles is obtained, even when the device is operated under harsh mechanical conditions. These results suggest that the as‐prepared CuCo 2 O 4 @MnO 2 /carbon fabric composite architecture is very promising for next‐generation high‐performance supercapacitors, and this work opens up a novel design of advanced integrated‐array electrode materials for high‐performance supercapacitors.